Publications

Early Detection of Emergent Extensively Drug-Resistant Tuberculosis by Flow Cytometry-Based Phenotyping and Whole-Genome Sequencing.

Date Published: April 27, 2019
A critical gap in tuberculosis (TB) treatment is detection of emergent drug resistance. We hypothesized that advanced phenotyping with whole-genome sequencing (WGS) will detect low-frequency drug resistance. We assessed a reporter mycobacteriophage (ΦGFP10) to detect drug-resistant subpopulations and predict bactericidal activity in this pilot study. Subsequently, we prospectively studied 20…

Investigation of ( S)-(-)-Acidomycin: A Selective Antimycobacterial Natural Product That Inhibits Biotin Synthase.

Date Published: April 12, 2019
The synthesis, absolute stereochemical configuration, complete biological characterization, mechanism of action and resistance, and pharmacokinetic properties of ( S)-(-)-acidomycin are described. Acidomycin possesses promising antitubercular activity against a series of contemporary drug susceptible and drug-resistant M. tuberculosis strains (minimum inhibitory concentrations (MICs) = 0.096-6.2 μM) but is inactive against nontuberculosis mycobacteria…

Whole genome sequencing identifies bacterial factors affecting transmission of multidrug-resistant tuberculosis in a high-prevalence setting.

Date Published: April 3, 2019
Whole genome sequencing (WGS) can elucidate Mycobacterium tuberculosis (Mtb) transmission patterns but more data is needed to guide its use in high-burden settings. In a household-based TB transmissibility study in Peru, we identified a large MIRU-VNTR Mtb cluster (148 isolates) with a range of resistance phenotypes, and studied host and…

Tuberculosis drugs’ distribution and emergence of resistance in patient’s lung lesions: A mechanistic model and tool for regimen and dose optimization.

Date Published: April 2, 2019
The sites of mycobacterial infection in the lungs of tuberculosis (TB) patients have complex structures and poor vascularization, which obstructs drug distribution to these hard-to-reach and hard-to-treat disease sites, further leading to suboptimal drug concentrations, resulting in compromised TB treatment response and resistance development. Quantifying lesion-specific drug uptake and pharmacokinetics…

An NAD Phosphorylase Toxin Triggers Mycobacterium tuberculosis Cell Death.

Date Published: March 21, 2019
Toxin-antitoxin (TA) systems regulate fundamental cellular processes in bacteria and represent potential therapeutic targets. We report a new RES-Xre TA system in multiple human pathogens, including Mycobacterium tuberculosis. The toxin, MbcT, is bactericidal unless neutralized by its antitoxin MbcA. To investigate the mechanism, we solved the 1.8 Å-resolution crystal structure of…

Transmission of drug-resistant tuberculosis in HIV-endemic settings.

Date Published: March 13, 2019
The emergence and expansion of the multidrug-resistant tuberculosis epidemic is a threat to the global control of tuberculosis. Multidrug-resistant tuberculosis is the result of the selection of resistance-conferring mutations during inadequate antituberculosis treatment. However, HIV has a profound effect on the natural history of tuberculosis, manifesting in an increased rate…

: Bacterial Fitness within the Host Macrophage.

Date Published: March 1, 2019
has evolved to become the single greatest cause of death from an infectious agent. The pathogen spends most of its infection cycle in its human host within a phagocyte. The bacterium has evolved to block the normal maturation and acidification of its phagosome and resides in a vacuole contiguous…
Courtesy of the U.S. National Library of Medicine